Introduction. This is a study of hierarchical navigation; how users browse a taxonomy-based interface to an organizational repository to locate information resources. The study is part of a project to develop a taxonomy for an library and information science department to organize resources and support user browsing in a digital repository.Method. The data collection was carried out using task-based navigation exercises with twenty-two participants. A cognitive framework of hierarchical navigation is proposed, involving the cognitive process of matching context, topic and/or resource type concepts to taxonomy categories.Results. Though users often use the topic concept in making navigation choices, they sometimes make use of context and resource-type concepts. Users infer a variety of relationships between a task concept and a taxonomy category, including the application area, associated tool, associated process/procedure/technique, associated institution and academic discipline.Conclusions. Users prefer to use common or generic associations in selecting categories to browse, rather than formal disciplinary relations. Some users prefer to search by people groups, contexts and institutions, rather than by subject categories. Users have difficulty distinguishing between various kinds of document and resource types.

Excerpt from the Conclusion section

The lessons we have learnt from the evaluation study can be summarized as follows:

Users are prepared to explore multiple navigation paths to locate a resource. Some users explored various top-level categories to understand them, before performing the tasks. Similar behaviour was observed by Large et al. (2009), who found that several children using the Canadian history portal tried all the top-level categories.

Users are creative in inferring a variety of relationships between a task concept and a taxonomy category. The relationships include application area, associated tool, associated process, procedure or technique, associated institution and academic discipline. It is not easy to predict which relationship a user will find salient and which top-level category the user will find relevant. Large et al. (2009) found that students sometimes had trouble selecting the top-level entry point to the taxonomy. Canoes was occasionally sought under Aboriginal peoples rather than Transport, and Vaccines under Everyday life rather than Science and technology.

Users associate topics with the contexts (e.g., courses) in which they encountered the topic and may not understand the formal disciplinary relations found in subject classification systems. Users prefer to use common or generic associations.

Some users are not familiar with browsing a subject classification system, and may prefer to search by people groups, contexts and institutions.

Users have difficulty distinguishing between various kinds of document types, resource types and formats. Certain resource types are associated with particular scenarios or contexts, for example Course material types with Courses. Rather than providing separate facets for different kinds of resource types, they should be used as subdivisions for the associated contexts.

Some users are lazy and will not explore complex structures or long lists of items.

We have assumed that a user’s information need can be represented as a context-topic-resource type triple, and that navigating a taxonomy-based interface involves a cognitive process of matching the task concepts to the taxonomy categories. The user can opt to use either the context, topic or resource-type concept for the matching and navigation. Though users most often used the topic concept in making navigation choices, they did make use of the context and resource-type concept quite frequently. For some users, the context or resource-type concept was somehow salient or seemed a good top-level category to start the navigation. When and why users decide to use the context, topic or resource-type is not known, and merits further study.